Punching-dies.



E. E. ROBERTS.

PUNGHING DIES.

APPLIUATIGN FILED MAR. 1, 1911.

Patented Dec. 16, 1913.

; )rbg WiTNESSE-Ifi I WM TINTTED %TATE% PTENT FETCH EDWARD E. ROBERTS 0FWHEELING, WEST VIRGINIA, ASSIGNOR 'IO STEEL FIRE- PROOFING COMPANY, ACORPORATION OF WEST VIRGINIA.

PUNCHING-DIES.

Specification of Letters Patent.

Patented Dec. 18,1913.

Application filed March 1, 1911. Serial No. 611,639.

dies for slitting sheet metal preparatory to.

expanding the same.

The object of the invention is to improve dies of this character indetails hereinafter described and claimed, and particularly to providsimple and efiicient means for stripping the slit sheets from thecutters.

The invention comprises the construction and arrangement of partshereinafter described and claimed.

in the accompanying drawings Figurel is in part a side elevation and inpart a vertical longitudinal section on the line 1-1, Fig. 2, showingdies constructed according to my invention; Fig. 2 is' a plan view ofone of the-dies with the stripper bars omitted; and Fig. "3 is atransverse section on the line 33, Fig. 2.

The improved dies are preferably used in oppositely arranged pairs, thatis a lower die 1 and an upper die 2. Each die comprises a suitableholder or-die block 3 arrangcd to be suitably connected to any suitablemechanism for imparting to the dies the necessary movements ofproximation and separation. 'The holder or die block is provided withone or more recesses i for receiving the cutters 5, the latter being inthe fornrof flat plates provided at their protruding ends with cuttingedges. The cutters of the two series have their cutting edges out ofalinement, that is the cutting edges of one series beingn'iidway'bctween the cutting edges of adjacent cutters on the otherseries, as shown in Fig. 2,'so as to provide the sheet with rows ofslits. with the slits of adjacent rows overlapping or alternating onewith the other, so that when expanded a diamond mesh is formed. Theseplates are placed in the recesses one against the other, or if desiredwith suitable spacers or shims therebctu'een, and are held in positionin the recesses by being clamped tightly one against the other bysuitable means, such as screws 6 working in tapped holes in the endportion of the holder or die block and at their inner ends bearingagainst the endmost cutters or preferably against following blocks 7 inthe recesses 4. The outer ends of the screws are square or otherwiseshaped for the attachment of, a wrench or key for turning the screws.The end of the holder or die block is provided with suitable-recesses 9into which the outer ends of the screws 6 project. The holders or dieblocks are also provided with vertical bushings 10 for receivingsuitable guide-pins for guiding the holders in their reciprocatingmovements in order to guide the edges of the cutters into shearingrelation.

Suitable strippers are provided for stripping the slit shects from thecutters, and preferably a stripper bar is provided at each side of eachrow of cutters. As shown the holder is provided with three longitudinalrecesses 11, one on each side of the holder and one between the two rowsof cutters. in the two outside recesses are located stripper bars 12which extend fairly close to the ends of the holder, and between the tworows of cutters is the center stripper bar 13 which is shorter onaccount of the bushings 10. Each stripper is substantially the length ofits recess and is guided in its up and down movement by means of aplurality of pins 14 reciprocating in holes formed from the holder andhaving one end riveted or otherwise suitably attached to the stripperbar and having secured to their outer ends suit able adjustable collars15 moving in recesses 16 in the outer faces of the holders or dieblocks. As shown these collars are in the form of nuts threaded onto thepins and provided with suitable recesses 17 for receiving a spannerwrench or other tool for rotating the same. The stripper bars arepressed outwardly, that is to strip the slit sheet from the cutters, bymeans of springs 18 surrounding the pins 14 and seated in pockets 19 inthe outer faces of the holders or die blocks. These springs yield whenthe dies come together, permitting the stripper bars to move down intothe recesses 11 in the holders or die blocks, but as soon as the diesseparate these springs lift the stripper bars out of their recesses andstrip the sheet from the cutters. The nuts or collars 1:) limit; theextent of such lifting movement of the stripper bars.

The dies described are of simple comtruc tion. the cutters are securelyheld in the lltl I i,oei,si7

holders or die blocks and effective means are provided for stripping theslit sheet from the cutters.

What I claim is:

1. In a sheet-metal slitting machine, the combination of upper and lowerdie members movable with reference to each other and each comprising, aholder, a plurality of cutters, a stripper bar seated. in the holder,and springs for moving said stripper bar out of its recess in saidholder, the cutters on the respectivedie members being arranged to shearparallel closed slits in a sheet and the stripper bars in said diememhers being disposed opposite to each other and arran ed upon movementof said dies to hold said sheet While being slitted and then strip thesame from said cutters.

2. In a sheet-metal slitting machine, the combination of upper and lowerdie members movable with reference to each other and each comprising, aholder, a row of par allel knife-edged cutters, a movable stripper barseated on each side of said row of cutters, springs for moving saidstripper bars out of said holders, the cutters on the respective diemembers being arranged in cooperative relation to each other and adapted to shear parallel. closed slits in a sheet,

and the stripper bars in said die members being disposed in pairsopposite to each other and arranged upon movement of said dies to holdsaid sheet while being slitted and to then strip the same from saidcutters.

3. in a sheet-metal slitting machine, the combination of upper and lowerdie members movable with reference to each other and each comprising, aholder, two sets of sheet, and the stripper bars in said die mem-.-

here being disposed opposite to each other and arranged upon movement ofsaid dies to hold said sheet while being slitted and strip the same fromsaid cutters.

In testimony whereof, I have hereunto set my hand.

EDW'ARD E. ROBERTS. Witnesses:

R. 0. Resume, ll'AnLiii GOLDEN.

